Recon:M18 Smoke Grenade
Disperses a cloud of smoke after detonation. Essential to mark improvised LZs, to vector the Cobra attack helicopter or just to conceal movement/hide. The cloud will only last for a few seconds, so bring a few if you plan to use them to block line of sight.
Alternatively, one can use Artillery to smoke a position and block line of sight. Obviously the M18 will provide faster results, but there will be less smoke. Used right, a commander can make great use of smoke, whether it be to shield rangers, mark targets, or designate a secondary LZ.
The M18 smoke grenade is a very simple concept. If one required smoke for any of the above reasons, they could easily throw this to that position. First developed as a replacement to the World War 2 smoke grenade, the M18 provided thicker, more vivid results and produced smoke for a longer period of time. They also came in an assortment of colors for different uses.